Office buildings consume 40% of the energy used in the United States, and 70% of the electricity used in the United States. Energy consumption, whether electrical, fossil fuel, or other energy usage, has become a topic of concern, not only for efficient use of resources but also for the global impact that energy consumption has taken on.
Since interest in efficient use of energy is high, technologies and tools that support the design of comfortable, clean, and efficient buildings have been in use for many years. However, the inherent time and length scales for such technologies and tools are generally relatively long (hours, days, large building spaces) and the performance expectations for these tools are averaged over time and large spatial domains.
For example, occupants of a building are rarely interested in the fine details of the temperature in a room as long as the temperature is kept within prescribed boundaries, while owners of the building are merely interested in keeping their overall monthly energy costs to a minimum. However, this situation changes dramatically when recent increases in energy costs and concerns about environmental impacts are taken into account.
Many existing efficiency-improving methods seek to achieve global building efficiency by optimizing individual building energy system components or subsystems. For example, more efficient compressors are used as retrofits for air conditioning systems, timed thermostats are used to anticipate building occupancy, or systems are given priority rates from utility companies if the utility company can shut down or minimize energy deliveries in the event of a surge in energy requirements in the area. Such approaches do not take a systems approach to building management or design, which would allow for even larger savings than retrofitting and variable usage conditions currently in use. Accordingly, there is a need for a more comprehensive building energy analysis system.